One Difference Between Posttraumatic Stress Disorder (PTSD) and Phobias Is

One difference between posttraumatic stress disorder (PTSD) and phobias is that:

A) with PTSD, the fear is triggered by a specific stimulus, whereas with phobias the fear is triggered by a wide variety of stimuli.
B) with phobias, the fear is triggered by a specific stimulus, whereas with PTSD the fear is triggered by a wide variety of stimuli.
C) PTSD, but not phobias, can be explained by classical conditioning.
D) phobias, but not PTSD, can be explained by classical conditioning.